JP2010517789A - Method for refractory assembly of carbon material and copper alloy - Google Patents

Abstract

The present invention relates to a method of assembling at least one member made of a porous carbon material and at least one member made of a copper-rich metal material, and an alloy paste used for carrying out the method. In order to assemble at least one member composed of a porous carbon material and at least one member composed of a copper-rich metal material, the method according to the present invention can be represented by the formula I Cu _x Si _y , where x and y are Including the use of copper and silicon based alloys with 25 ≦ x ≦ 60, 40 ≦ y ≦ 75 and x + y ≧ 95%. The invention is particularly suitable for use in the field of thermal engineering.
[Selection figure] None

Description

  The present invention relates to a method of assembling at least one member made of a porous carbon-based material and at least one member made of a copper-rich metal material, and an alloy paste for carrying out the method.

  An assembly referred to as a refractory assembly is an assembly of components having a service temperature in excess of 500 ° C.

These assemblies are very interesting in the thermal engineering field. They order to have a high energy exchange density of ^{10MW / m 2 ~20MW / m 2} , can be used in the manufacture of the heat exchanger components. Energy is generated with very high power on the “carbon-based material side” (which is highly fire resistant), while active cooling systems such as cooling by circulating coolant (with low fire resistance) Heat is recovered on the “copper side”.

  For this reason, in this type of assembly it is important to ensure both a very good heat exchange between the various members making up the assembly and a very good mechanical bond.

  These assemblies are generally assemblies comprising a member made of a copper-rich material together with a member made of a porous carbon-based material.

  In the context of the present invention, the term “porous carbon-based material” is understood to mean a material comprising at least 50 wt% carbon, preferably more than 80 wt% carbon, and most preferably 100% carbon.

  This type of material can be graphite, glassy carbon, a composite made of carbon fibers in a carbon-based matrix, and the like.

  Similarly, the expression “copper rich metal material” is understood in the present invention to mean a material containing at least 50 wt% copper, preferably more than 80 wt% copper, and more preferably pure copper. .

  Finally, the term “porous material” is understood to mean a material having an open area greater than 5% and less than 50% by volume of the material of interest.

  In order to manufacture this type of assembly, an assembly method has been proposed in which two members are bonded together using an organic adhesive. However, the service temperature of these types of assemblies never exceeds 200 ° C., which makes them unsuitable as refractory assemblies.

  It has also been proposed to produce the assembly by a purely mechanical method by stapling, screwing, interlocking or riveting. However, these assemblies result in much lower heat transfer due to partial and random contact between the two members.

  It has also been proposed to assemble the two members of a refractory assembly by bringing about atomic interdiffusion between the two members by fusion welding, i.e., applying pressure to the interface between the two members at an elevated temperature. . In this method, the temperature must always be maintained below the melting point of the lowest refractory material. Therefore, there is no liquid phase in this system. This type of assembly is performed in a press, which is pressurized in one direction, or in a static pressure chamber. Fusion welding is well suited for the assembly of two alloys, but is not suitable when refractory ceramic materials are present because the ceramic constituent atoms diffuse very little at the joint. However, diffusion welding also does not allow partial metal penetration into the pores of the ceramic material, so it is impossible to obtain a very good heat exchange between the two members and a very good mechanical bond. It is.

  Therefore, in order to ensure good heat transfer and good mechanical adhesion in the assembly, only a method using a liquid phase that can partially penetrate the porous carbon-based component at the joining surface is foreseen. Cannot be done.

To this end, in some cases, in all cases, brazing, ie in a high vacuum of less than 10 ⁻⁴ mbar or in an inert gas such as argon, shielded from oxygen in the air Reactive brazing that requires melting of the wax (in any of the above) has been used.

  Therefore, Patent Document 1 discloses that 86% to 99.5% by weight of at least one reactive element selected from copper, silver, nickel, and aluminum and vanadium, niobium, and titanium as brazing alloys. It proposes joining carbon-based compounds to metallic materials by using a brazing alloy consisting of 0.5 to 10% by weight of elements selected from zirconium and silicon . In this method, a brazing alloy is provided on a joint surface between a member made of a carbon composite material and a member made of a metal material, and the entire assembly is heated in a vacuum at a temperature of 850 ° C. to 980 ° C. for 10 minutes.

  In addition, by containing a reactive element such as titanium or zirconium in such a ratio, silver or copper that guarantees good infiltration of most ceramic substrates, particularly carbon-based ceramics such as graphite or carbon-carbon composites, It has been proposed to use brazing materials called reactive brazes based on them.

  However, the main drawback of reactive brazing is the randomness of penetration that actually depends on the randomness of the pores of the carbonaceous material. In other words, at a single joint surface, a zone of high penetration of the compound by brazing is observed beside the zone that is only slightly impregnated, which leads to vacancies at the joint. There is a possibility. In this case, heat transfer remains low due to possible “hot spots” that occur during the work. Similarly, in the case of thermal shock, the mechanical fixation is somewhat inferior with the risk that the carbon-based compound will desorb or delaminate from its support.

  As a result, even if this fixation can yield useful results, it is not reliable for considering industrial applications.

  In order to improve this method, U.S. Patent No. 6,057,059 proposes to manipulate the surface of the permeating porous material to artificially increase the area of carbonaceous material / brazing exchange. This is carried out by laser machining and creates regular perforations with conical holes with a diameter of 50 μm to 500 μm, a depth of 100 μm to 2 mm and a spacing between perforations of 0.25 mm. . This arrangement of perforations makes it possible to ensure a very homogeneous distribution of the penetration of the reactive brazing material. Proposed brazing materials are generally based on silver and copper, which are activated by a few percent of titanium. Although the proposed machining surface treatment solves the problem of reliability of reactive brazing filler metal, its large-scale use still remains a problem, even if automated, due to cost and time of operation.

  Furthermore, Non-Patent Document 1 studies the reactive infiltration of an alloy composed of 40 atomic% silicon and 60 atomic% copper on a glassy carbon substrate or silicon carbide substrate. This paper shows that the infiltration by the Cu-Si system on the glassy carbon substrate is good.

  However, this infiltration alone does not guarantee homogeneous penetration of the porous substrate nor good mechanical adhesion of the carbon / Cu—Si / copper alloy joint. This is because, for example, excessively good infiltration of the brazing material carries the risk of promoting its complete absorption by the porous carbon-based substrate, thereby resulting in an assembly with a copper alloy. Is impossible. In addition, there is no information regarding the permeability of glassy carbon, and in fact, there is no information regarding the assembly of a member made of a porous carbon-based material and a member made of a copper-rich metal material.

US Pat. No. 5,340,658 US Pat. No. 6,160,090

"Mechanisms of reactive wetting: the question of triple line configuration", Acta Mater. Vol. 45, No. 7, p. 3079-3085, 1997

  The present invention is industrially applicable and proposes the use of a copper alloy to assemble at least two parts by a reliable and inexpensive method. The purpose is to alleviate the drawbacks.

  To this end, the present invention uses both a braze alloy that penetrates partially in liquid phase form into a porous carbon-based material, in particular, for both mechanical adhesion and good heat transfer in the resulting final assembly. Propose to guarantee.

  The braze alloy used in the present invention contains 25 atomic% to 60 atomic% copper and 75 atomic% to 40 atomic% silicon, which includes about 12.8 wt% to 39.9 wt% Si and It corresponds to 87.2 wt% to 60.1 wt% Cu, and the total atomic ratio of Si and Cu corresponds to at least 95%.

  If a small amount of silicon is used, the infiltration is very poor and not satisfactory from the point of view of brazing. The reason for this is that the low infiltration results in poor filling of the joint brazed with the brazing material or creates holes in the joint. Good infiltration is essential but not sufficient for successful brazing.

  On the other hand, when the silicon content in the brazing alloy exceeds 40 wt%, the penetration of the porous carbon-based compound is not well controlled and the quality is low.

  One particularly preferred brazing alloy for use in the present invention is a brazing alloy containing 40 atomic percent silicon and 60 atomic percent copper.

  This alloy is particularly suitable for assembling members made of porous carbon-based materials and members made of copper-rich materials.

  The braze alloy used in the present invention provides good infiltration of components made of porous carbon-based materials, but surprisingly despite the good infiltration on carbon in systems containing high amounts of silicon. First, the slow penetration of the brazing alloy of the present invention into the porous carbon-based material allows the brazing alloy to penetrate into the fully controlled porous carbon-based substrate. Makes it possible to achieve homogeneous penetration (controlled to be partial with respect to the pores) of the brazing alloy into the porous carbon-based compound.

  This complete control of braze alloy penetration prevents complete consumption of the braze alloy in its pores by the carbon-based substrate, and some of the braze alloy forms a coating on the surface of the porous carbon-based material. Guarantee that.

  This is because the brazing alloy can be maintained at a thickness of 100 μm on the surface of the porous carbon-based material after the brazing alloy is melted on the porous carbon-based material. Therefore, the braze alloy can still be used to actually assemble with a copper rich metal material.

  Surprisingly, since the reaction zone is very thin and is generally less than 1 μm, moderate reactivity between the brazing alloy and carbon during the permeation of the porous carbon-based material was observed. However, Cu-Si systems are known for reactivity, and silicon reacts with carbon to synthesize silicon carbide. For example, in the case of carbon-carbon composites that incorporate carbon fibers, fiber integrity is maintained even in the infiltration zone, and even if contact occurs between the braze alloy and carbon, the carbon fiber is eroded or damaged by the braze alloy. Absent.

The braze alloy used in the present invention can be prepared by melting copper and silicon in the desired atomic ratio in an alumina crucible. The mixture is melted in a furnace at a temperature of 1000 ° C. to 1200 ° C. under a vacuum of 10 ⁻² mbar to 10 ⁻⁵ mbar or in an inert gas for 10 minutes to 30 minutes. After cooling the resulting molten product, the cooled product is preferably ground.

  When the particle size of the brazing alloy powder is 100 μm to 500 μm, good results were obtained when the brazing alloy of the present invention was used.

  For a more practical and uniform application on the assembled parts, this powder is mixed with an organic binder to obtain a brazing paste according to the invention having a consistency that allows it to be widely spread. Also good. Suitable binders are known to those skilled in the art. An example of such a binder is Microbraz Cement® 650 in an amount of 10% to 20% by volume.

  The braze alloy of the present invention also comprises a silicon powder having a purity of about 98% by blending a commercial Cu-Si alloy with the required amount of silicon powder to obtain the desired Cu and Si atomic ratio. From a blend with a commercial Cu-Si alloy having a purity of about 98%. It is recalled that these ratios are 25 atomic% to 60 atomic% silicon and 75 atomic% to 40 atomic% copper.

  As before, the blend is then melted in the oven in a vacuum or in an inert gas for the same time at the same temperature as described above.

  After cooling the resulting molten product, a paste having a consistency that allows the cooled product to be ground and then blended with an organic binder to spread widely on the surface of the assembling member. May be obtained.

  The method of assembling at least one member made of a porous carbon-based material and at least one member made of a copper-rich metal material includes at least one step using the metallized alloy of the present invention.

More precisely, the brazing alloy of the present invention is applied to the surface of a member made of a porous carbon-based material to be assembled, either in powder or paste form. This porous carbon-based material is previously deaerated in a high vacuum at a temperature of 1300 ° C. to 1400 ° C. Preferably, the assembly surface, an alloy of 1 cm ² per 50 mg to 500 mg, and most preferably coated with an alloy of 1 cm ² per 100Mg～400mg. Thereafter, the brazing alloy of the present invention is melted and infiltrated into the porous carbon-based material. For this purpose, a member made of a porous carbon-based material is coated on the assembly surface with the brazing alloy of the present invention or the brazing paste of the present invention and placed in a vacuum furnace to melt the brazing alloy of the present invention. Heat to a temperature that can.

Such temperatures are generally 1000 ° C to 1200 ° C. The heat treatment time for melting this alloy is 30 minutes to 90 minutes. The vacuum used is a high vacuum of 10 ⁻² mbar to 10 ⁻⁵ mbar. However, an inert gas stream such as argon having an oxygen content of less than 5 ppm may be used.

  Surprisingly, after this operation, the braze alloy penetrated homogeneously over the entire assembly surface of the member made of porous carbon-based material so that it was completely controlled. The observed penetration into the porous carbon-based substrate depends on the temperature and time of the heat treatment, together with the brazing alloy film on the surface having a thickness of 100 μm to 2000 μm, depending on the temperature and time of the heat treatment. It has a depth of 500 μm to 1000 μm.

Therefore, the next step of the method of the present invention is to perform the actual assembly of a member made of a porous carbon-based material whose assembly surface is coated with a molten braze alloy and a member made of a copper rich metal alloy. is there. For this purpose, the surface of the member made of the porous carbon-based material coated with the brazing alloy is lightly polished and then brought into contact with the assembly surface of the member made of the copper-rich metal material. The entire assembly is then heated in vacuum or in an inert gas at a temperature below the melting point of the copper rich metal material and below the temperature at which the braze alloy is completely melted. However, this temperature is 802 ° C., the lowest in the copper-silicon binary composition diagram, so that the liquid phase can temporarily occur at the point of contact between the metal and the metallized surface of the carbon-based compound. Must be higher than the eutectic temperature. This operation is called “eutectic brazing”. Preferred operating parameters for this second thermal cycle are treatment at 850 ° C. to 950 ° C. in a high vacuum of 10 ⁻² mbar to 10 ⁻⁵ mbar or in an inert gas stream such as argon having an oxygen content of less than 5 ppm. The temperature and the processing time from 10 to 30 minutes.

  After this second thermal cycle corresponding to the assembly of the two parts, the assembly is effective when the object is cooled to room temperature. Eventually, an assembly made in accordance with the present invention can then be incorporated into a heat exchanger or any other unit by mechanical (screwing, riveting) methods or by welding or diffusion welding or brazing. .

  The assembly obtained by the present invention is composed of a member made of a porous carbon-based material and a member made of a copper-rich metal material having a molten brazing alloy according to the present invention on a joining surface for joining the members. The assembly method of the present invention results in very good mechanical fixation and very good heat transfer between the carbon-based substrate and the copper substrate, resulting in very good thermal shock resistance even under extreme conditions. Guarantee that there is.

  Another notable characteristic of the assembly method of the present invention is that the penetration into the porous carbon-based material is homogeneous despite the initial heterogeneity of the porous carbon-based material. This is because carbon-carbon composites are particularly inhomogeneous, for example, a large number of holes are randomly scattered in an array of knitted carbon fibers. The penetration obtained by the method of the present invention shows that the penetration depth is the same whether in a zone containing high density fibers or vice versa, in a zone containing low density fibers with more pores. ing.

  Also, according to the method of the present invention, the penetration of copper into the porous carbon-based material is accomplished without machining the assembly surface, thereby significantly reducing the cost of the assembly operation.

  Finally, one notable advantage of braze alloy formulations that “metallize” porous carbon-based composites is that the number of chemical elements that perform assembly is very limited. This eliminates the multicomponent metal system that occurs at high temperatures and eventually becomes brittle with the formation of numerous intermetallic compounds. Indeed, the only chemical elements used in the braze alloy of the present invention are carbon, copper and silicon.

The brazing method and brazing paste of the present invention are particularly applicable in the field of thermal engineering, especially for very high performance heat exchanger parts capable of handling high heat fluxes of about 20 MW / cm ^2. is there. At the time of exchange between the first circuit and the second circuit, it is essential to use materials suitable for two thermal circuit environments that are resistant to the operating temperature and have a very high thermal conductivity, This is an example of carbon materials and copper materials.

  For this reason, since the carbon-based materials are resistant to the extreme conditions of high heat flux heat exchangers, the methods and alloys of the present invention are particularly targeted at the manufacture of high heat flux heat exchangers that recover energy in the plasma. And The basic principle of this type of device is to recover the energy released by the plasma obtained by the thermonuclear reaction using a protective shield consisting of a panel of carbon-carbon composite tiles. Heat is recovered through a carbon tile cooling circuit made using a series of copper tubes. The copper tube structure must be actively cooled by circulating a coolant so that the temperature of the metal is kept moderate (less than 1000 ° C.). This type of thermal equipment is used very extensively in tokamak and toroidal plasma confinement equipment, which develops future thermonuclear power plants that study plasma and operate on the basis of fusion principles It is equipment to do.

  For this reason, the invention also relates to a device comprising at least one assembly according to the invention.

  The present invention will be better understood and other advantages of its features will become more apparent upon reading the following exemplary embodiments, which are given merely as examples of the present invention but are not meant to imply limitations thereof .

Example 1
Preparation of Carbon-Carbon Composite / Pure Copper Assembly This example illustrates the manufacture of an assembly of a C / C composite and a pure copper plate.

The member dimensions are:
C / C composite: 20 × 15 × 8 mm ³ ;
Copper: 20 x 15 x 2mm ³
Met.

  The C / C composite material was a carbon matrix composite material reinforced with carbon fiber (supplier: SNECMA; material product number: NB31).

The C / C composite material was washed in an ultrasonic degreasing (organic solvent) bath and then dried. The composite was then degassed during vacuum heat treatment under vacuum of 10 ⁻² mbar to 10 ⁻⁵ mbar at 1420 ° C. for 1 hour.

  The copper plate was washed in an ultrasonic degreasing bath and then dried.

  In the first step, a brazing alloy having a composition of 60 atomic% Cu / 40 atomic% Si was produced from the powder. The alloy was then blended with an organic binder to obtain a paste.

  In the second step, the C / C composite surface to be brazed was coated with this brazing paste. The amount of brazing was preferably 800 mg to 1000 mg.

The composite was then placed on a support (alumina or graphite plate) in the furnace and subjected to thermal cycling. The heat treatment conditions are:
Holding temperature: 1160 ° C;
Retention time: 60 minutes;
Atmosphere: High vacuum.

  After holding, the cooling was natural cooling.

This process:
Melting of the alloy;
Penetration of the alloy into the composite to a depth of about 1.5 mm;
Coating of the composite assembly surface with a continuous alloy thickness (about 500 μm); and a very limited reaction of carbon with the alloy, ie a reaction zone that was about 1 μm.

The third step consisted of brazing the Cu—Si metallized composite and pure copper. The metallized composite surface that was brazed so that the metallized composite and the copper plate were in full contact was lightly polished. Next, the metallized surface of the composite material was covered with a copper plate to which no brazing paste was applied. The entire assembly was then placed on a support (alumina or graphite plate) in the furnace and subjected to thermal cycling. The heat treatment conditions are:
Holding temperature: 900 ° C;
Holding temperature: 15 minutes;
Atmosphere: High vacuum.

  After holding, the cooling was natural cooling. After removal from the furnace, the C / C composite was assembled with a pure copper plate.

Example 2
Preparation of an assembly comprising the assembly obtained in Example 1 and a member made of a 98.97 wt% Cu / 0.84 wt% Cr / 0.14 wt% Zr composition CuCrZr alloy. Assembled with alloy parts.

  The surface of the CuCrZr member to be assembled with pure copper was electroplated with nickel. Next, it was arranged so as to face the pure copper member. The entire assembly was placed in a metal container under vacuum and sealed with TIG (tungsten inert welding). Sealing of the sealed container was confirmed using a helium test. Once sealed, the container was placed in a HIP (hot isostatic pressing) chamber and subjected to 120 minutes heat treatment: temperature: 550 ° C .; pressure: 400 bar. After the HIP cycle, the container was opened. What was obtained was an assembly of CuCrZr and pure Cu that was itself bonded to the C—C composite.

Example 3
Preparation of Carbon-Carbon Composite / CuCrZr Alloy Assembly This example illustrates the assembly of a carbon-carbon composite and a plate of 98.97 wt% Cu / 0.84 wt% Cr / 0.14 wt% Zr composition CuCrZr alloy. Manufacturing will be described.

The member dimensions are:
Carbon-carbon composite material: 20 × 15 × 8 mm ³
CuCrZr: 20 × 15 × 10 mm ³
Met.

  The carbon-carbon composite was a carbon matrix composite reinforced with carbon fiber (supplier: SNECMA; material product number: NB31).

The carbon-carbon composite material was washed in an ultrasonic degreasing (organic solvent) bath and then dried. The composite was then degassed during vacuum heat treatment under vacuum of 10 ⁻² mbar to 10 ⁻⁵ mbar at 1420 ° C. for 1 hour.

  The CuCrZr plate was washed in an ultrasonic degreasing bath and then dried.

  In the first step, a brazing alloy having a composition of 60 atomic% Cu / 40 atomic% Si was produced from the powder. The alloy was then blended with an organic binder to obtain a paste.

  In the second step, the carbon-carbon composite surface to be brazed was coated with this brazing paste. The amount of brazing was preferably 800 mg to 1000 mg.

The composite was then placed on a support (alumina or graphite plate) in the furnace and subjected to thermal cycling. The heat treatment conditions are:
Holding temperature: 1160 ° C;
Retention time: 60 minutes;
Atmosphere: High vacuum.

  After holding, the cooling was natural cooling.

This process:
Melting of the alloy;
Penetration of the alloy into the composite over a depth of about 1.5 mm;
Coating the assembly surface of the composite with a continuous alloy thickness (about 500 μm); and a very limited reaction between carbon and the alloy, ie a reaction zone that was about 1 μm.

The third step consisted of brazing the Cu—Si metallized composite and CuCrZr. The metallized composite surface that was brazed so that the metallized composite and the copper plate were in full contact was lightly polished. Next, the metallized surface of the composite material was covered with a CuCrZr plate to which no brazing paste was applied. The entire assembly was then placed on a support (alumina or graphite plate) in the furnace and subjected to thermal cycling. The heat treatment conditions are:
Holding temperature: 900 ° C;
Retention time: 15 minutes;
Atmosphere: High vacuum.

  After holding, the cooling was natural cooling. After removal from the furnace, the carbon-carbon composite was assembled with a CuCrZr plate.

Example 4
Thermal shock resistance testing of assemblies obtained with the inventive alloys by the method of the present invention To test the mechanical strength of C / C / Cu-CrCrZr joints made according to the protocol described in Examples 1 and 2 The thermal shock experimental protocol was used.

  This protocol consists of heating the C / C / Cu—CuCrZr assemblies in argon from 20 ° C. to 450 ° C. and then subjecting them to water cooling (the basket containing the specimens was allowed to sink into the water). It was. This process was repeated 30 times for each specimen. After 10 cycles, an appearance inspection was performed. No joint rupture was observed after 30 thermal shocks on 4 identically made specimens (Protocol 1, then Protocol 2).

Example 5
The assembly obtained in Example 1 and an ODS (Oxide Dispersion Strengthened Type) composition with Cu / 0.25 wt% Al / 0.2 wt% O / 0.025 wt% B cured by Al ₂ O ₃ oxide dispersion. ) Preparation of an assembly consisting of Cu alloy The assembly obtained in Example 1 is then converted to an ODS Cu alloy (0.25 wt% Al / 0.2 wt% O / 0.025 wt% B) with dimensions 20 × 15 × 10 mm ^3. Assembled with a member consisting of This member was washed in a degreasing bath and then dried.

The pure Cu member surface obtained in Example 1 was coated with a brazing paste having a composition of 60 atomic% Cu / 40 atomic% Si. The amount of brazing was 100 mg. The assembly surface of the ODS Cu member was placed on the brazing material coating surface of the Cu member. The entire assembly was placed on a support (alumina or graphite plate) in the furnace and subjected to thermal cycling. The heat treatment conditions are:
Holding temperature: 900 ° C;
Retention time: 15 minutes;
Atmosphere: High vacuum.

  After holding, the cooling was natural cooling. At the time of removal from the furnace, the ODS Cu member was assembled with a pure Cu member that was itself assembled with a C / C composite. That is, a C / C-Cu-ODSCu assembly was obtained.

Example 6
Fabrication of an assembly of a carbon-carbon composite and an ODS Cu alloy member having a Cu / 0.25 wt% Al / 0.2 wt% O / 0.025 wt% B composition cured by Al ₂ O ₃ oxide dispersion The member dimensions are:
Carbon-carbon composite: 20 × 15 × 8 mm ³ ;
ODSCu: 20 × 15 × 10 mm ³
Met.

  The carbon-carbon composite was a carbon matrix composite reinforced with carbon fibers (supplier: SNECMA; material product number: NB31).

The carbon-carbon composite member was washed in an ultrasonic degreasing (organic solvent) bath and then dried. The carbon-carbon composite member was then degassed during vacuum heat treatment under vacuum at 10 ⁻² mbar to 10 ⁻⁵ mbar at 1420 ° C. for 1 hour.

  The ODS copper plate was washed in an ultrasonic degreasing bath and then dried.

  In the first step, a brazing alloy having a composition of 60 atomic% Cu / 40 atomic% Si was produced from the powder. The alloy was then blended with an organic binder to obtain a paste.

In the second step, the carbon-carbon composite surface to be brazed was coated with this brazing paste. The amount of braze preferably was ^{100mg / cm 2 ~400mg / cm 2} .

The composite was then placed on a support (alumina or graphite plate) in the furnace and subjected to thermal cycling. The heat treatment conditions are:
Holding temperature: 1160 ° C;
Retention time: 60 minutes;
Atmosphere: High vacuum.

  After holding, the cooling was natural cooling.

This process:
Melting of brazing alloy;
Penetration of the braze alloy into the composite to a depth of about 1.5 mm;
Coating the assembly surface of the composite with a continuous braze alloy thickness (about 500 μm); and a very limited reaction between carbon and the braze alloy, ie a reaction zone of about 1 μm.

The third step consisted of brazing the Cu-Si metallized composite member and the ODS copper member. The metallized composite surface to be brazed was lightly polished so that the metallized composite (brazing alloy layer) and the ODS copper plate were in complete contact. The metallized surface of the composite was coated with an ODS copper plate to which no brazing paste was applied. The entire assembly was then placed on a support (alumina or graphite plate) in the furnace and subjected to thermal cycling. The heat treatment conditions are:
Holding temperature: 900 ° C;
Retention time: 15 minutes;
Atmosphere: High vacuum.

  After holding, the cooling was natural cooling. At the time of removal from the furnace, the carbon-carbon composite member was assembled with the ODS copper plate.

Example 7
Thermal Shock Resistance Test The same protocol described in Example 4 was performed on the assemblies made in Example 3, Example 5 and Example 6. No bursting was observed after this test.

  The above examples include the method of the present invention, the use of a brazing alloy and a brazing paste that are particularly suitable for assembling a member made of a porous carbon-based material and a member made of a copper-rich material. However, the present invention is in no way limited to such components.

Claims (8)

For the assembly of at least one member made of a porous carbon-based material and a member made of at least one member made of a copper-rich metal material, the following formula:
Cu _x Si _y
(Wherein x and y are atomic ratios such that 25 ≦ x ≦ 60, 40 ≦ y <75 and x + y ≧ 95%)
Use of an alloy based on copper and silicon having   Use of an alloy according to claim 1, characterized in that x = 60 and y = 40. Following formula:
Cu _x Si _y
(Wherein x and y are atomic ratios such that 25 ≦ x ≦ 60, 40 <y ≦ 75 and x + y = 95%)
A brazing paste characterized in that it comprises a blend of a brazing alloy in powder form with an inorganic binder. A method of assembling at least one member made of a porous carbon-based material and at least one member made of a copper-rich metal material,
a) The amount of brazing alloy such that ^{50mg / cm 2 ~500mg / cm 2} , on the assembly surface of at least one member made of the porous carbon-based material, the following formula:
Cu _x Si _y
(Wherein x and y are atomic ratios such that 25 ≦ x ≦ 60, 40 ≦ y ≦ 75 and x + y ≧ 95%)
Depositing a copper and silicon based alloy, or depositing a brazing paste according to claim 3;
b) heating the entire assembly obtained in step a) in a vacuum or in an inert atmosphere so as to melt the alloy or the paste;
c) contacting the entire assembly obtained in step b) with the assembly surface of at least one member comprising the porous carbon-based material;
d) heating the entire assembly obtained in step c) in a vacuum or in an inert atmosphere at a temperature below the melting point of at least one member of the copper-rich metal material and below the melting point of the alloy or the paste; ,
A method for assembling at least one member made of a porous carbon-based material and at least one member made of a copper-rich metal material.   The assembly method according to claim 4, characterized in that the heating temperature of step d) exceeds 802 ° C.   Step c) is performed at a temperature of 1000 ° C. to 1200 ° C. for 30 minutes to 90 minutes in a vacuum or argon atmosphere, and step d) is performed at a temperature of 850 ° C. to 950 ° C. for 10 minutes to 30 minutes. 6. Assembly method according to claim 5, characterized in that it is carried out in a flow of argon or argon. The assembly has the following formula:
Cu _x Si _y
(Wherein x and y are atomic ratios such that 25 ≦ x ≦ 60, 40 ≦ y ≦ 75 and x + y ≧ 95%)
An assembly comprising at least one member made of a porous carbon-based material and at least one member made of a copper-rich metal material having a layer of a molten and solidified copper alloy having:   8. An apparatus comprising at least one assembly according to claim 7.